Requirements for both appearance and safe should be considered for aluminum wheels, putting forward a great challenge to wheel manufacturers. At the present stage, about 80% of aluminum wheels are produced by adopting a low-pressure cast molding process, which adopts a central injecting from bottom mode that high-temperature molten aluminum is driven by external pressure to enter a mold and solidified in a cavity to form a qualified casting having dimension and performance both meeting standards. As for wheel molding, junction R angles of the spokes and the rim are quite thick and large, belong to typical casting hot spots, and are also difficult and important in present production. A large number of practices show that rejects caused by R angle position defects account for over 70% of the total proportion, mainly because the wall of the casting therein is thick and heat is too concentrated therein, causing slow solidification of molten aluminum, whereas the front spoke wall is relatively thin, and the molten aluminum is quickly solidified to block a molten aluminum flow channel early, thereby hindering effective feeding on the hot spots and leading to molding defects such as loosening, shrinkage and the like; besides, relatively low degree of super cooling may result in thick and large grains and loose tissues of the casting, so that the mechanical properties are low, the wheel is difficult in passing subsequent reliability test, and the safety performance of the wheel is influenced. Meanwhile, the long solidification process prolongs the production cycle, improves the production cost and is unbeneficial to benign development of enterprises. Therefore, how to solve the molding problem of R angle positions is a puzzle for numerous wheel technologists.